Accounting for greenhouse gas emissions (GHG) is no simple matter in urban transport. It is not as simple as the GHG emissions from the vehicles themselves. For example, there is the vehicle manufacturing process. There is also vehicle maintenance and the energy used to keep stations and administrative facilities open. There is simply no central source of information for such data, a situation that is a serious “GHG omission.”
Three decades ago, BART, the San Francisco area rapid transit system, published estimates of the full energy requirements for operating public transport and cars, including such factors as vehicle maintenance, right of way maintenance, and stations. Generally, the analysis found that the rail mode required 41 percent more energy than is consumed in traction (transportation), buses 37 percent and cars 22 percent. These factors may be old, but they may be the only ones available (and it is possible that they are still valid).
If we assume the BART factors, then the comparison of GHG emissions between transport modes in Australia is even more favorable for cars. The average car would emit 229 grams of GHG per passenger kilometer, compared to 212 grams for buses and 148 grams for Sydney’s rail system. Cars meeting the 2010 National Average Fuel Consumption target would be better than both buses and rail in Sydney at 137 grams per passenger kilometer. The best hybrids could best buses by two-thirds and rail by one-half.
All of which points out the needed for objective, comprehensive analysis.
The previous post on GHG emissions by mode is shown below. The information in the previous post does not include any adjustment for vehicle maintenance, right of way maintenance, and stations. Its calculations apply only to transportation.
Guest Blog by Tony Recsei
Save Our Suburbs
Public Transport Greenhouse Emissions Similar to Cars
Contrary to the repeated claims of high-density advocates that public transport travel is environmentally far superior to travel in cars, it has now been found that this is not the case. Greenhouse gas emission data posted by Demographia shows that the average petrol car in Australia in 2006 emitted 188 grams CO2 equivalent per passenger km and the figure for the more efficient cars now is as little as 60 grams.
These figures should be compared with the average bus in Australia which emits 155 grams CO2 equivalent per passenger km and with the 105 grams for traveling by rail in Sydney.
The emission figures of the Toyota Prius and the Peugeot hybrid diesel cars are indications that even the surprisingly small advantage of public transport could soon be eroded away by technology.
The reality that public transport use is not significantly more environmentally sustainable is of huge importance for planning policies. For the past two decades the NSW State Government has been implementing a policy of forcing high-density into communities. The principal foundation of these policies has been the allegation that people living in high-density will be able to travel more sustainably by public transport instead of by car. We now know this is not so.
The rationale for the despotic policies that have destroyed home ownership and grossly overloaded existing infrastructure is baseless.